1. Field of the Invention
The present invention relates generally to swimming pools and, more particularly, to sealing apparatus for closing off the sidewall opening of a skimmer to prevent water from entering the skimmer when the pool is closed for the season.
2. Brief Description of the Prior Art
It is common to employ one or more skimming devices in the sidewalls of swimming pools, hot tubs and the like to permit surface water to be drawn off by a pump, to be filtered at a remote location and then optionally heated, and returned to the pool through one or more return ports. When the pool is closed during the winter season, for example, it is sometimes desirable to maintain a lower level of water in the pool for structural purposes. Even if completely drained, the water level in the pool will naturally rise during the closed season due to rainwater and melting snow, such that the water level oftentimes rises to a level of the skimmer opening or above. In such cases, it is necessary to close off the skimmer to prevent backflow of water through the skimmer conduit to the filtration, pump equipment, and heater so as to prevent damage to the pipes, filtration equipment, and heater due to freezing during the cold winter months.
One common way of closing off the skimmer is to employ an elongated plug-like element, marketed under the trademark “GIZMO®”. The plug element is threadably secured within the floor of the skimmer body to seal the conduit communicating with the pump and filtration equipment. Several other devices for sealing off a skimmer opening with a detachable cover plate or panel are disclosed in U.S. Pat. Nos. 4,913,810; 5,937,453; and 5,285,538. These prior devices either require a retrofit of the skimmer faceplate in order to make sealing contact with a closure member as in the '810 patent, or require the use of a polymeric flexible sealing member which snaps over the skimmer opening. Such faceplate seals may lose their effectiveness due to weathering of the polymeric material, and also may require special retrofitting of the skimmer opening member to provide better sealing between the skimmer and the flexible snap-on faceplate.